What is the best estimate for this product? 81*409?

What is the order of operations for 2 + (3 - 9) ÷ -3 · 4 in number order 1. subtraction 2. division 3. addition 4. multiplication

Which shows the correct substitution of the values a, b and c from the equation 1=-2x+3x^2+1

Richard save $32 in march he saved $48 in april and $38 in may then richard spent $113 on a keyboard how much money does richard have left